What Causes An Unusual Penile Discharge?

Hi, I'm 20 years old and have been sexually active with my girlfriend. We've stopped a month ago and since then, every once in a while, my penis ejects white fluid (when not erect) and I can notice it because some lint or fabric is stuck to the tip. This has happened to me before a long time ago and went away, but recently i've been thinking about it a lot. Is this normal?